As it turns out, in my own neck of the woods there is a small woo-factory. I came upon it when I saw an internet add extolling the virtues of salt, as long as it’s expensive salt. The author of the article turns out to be a doctor in my very metropolitan area. There is so much woo here that it may take a few posts to get through it all.
The article is called “Salt Your Way to Health” and is featured on the website for a company that just happens to sell, well, fancy salt. There is a bit of a cage match going on with my internal writer and internal scientist. To properly deconstruct and critique this article would create an unreadably long post. So please indulge me with a little patience as I toe the lines of readability and de-wooification.
Salt and Hypertension
Before firing up the de-wooificator, I’m going to have to tell you a little bit about salt and hypertension. Sodium chloride (salt) is essential to human life. Salt is the primary extracellular electrolyte in the body, and we can’t live without it. Common American table salt also contains trace amounts of added iodine to prevent goiters. That being said, consuming too much salt has health consequences. First, in people with congestive heart failure, too much can make it difficult to breath, and even kill.
When it comes to hypertension, salt consumption has been studied extensively. Most of this information is available for free and is summarized in the JNC VII Report on hypertension, a summary of which can be found here. High blood pressure kills and disables millions of Americans every year, mostly via strokes and heart attacks. It has no symptoms, but is easily treated. It is one of the best-studied human medical problems. Lowering blood pressure has been shown to lower the risks of stroke, heart attack, and other hypertensive-related diseases.
Prevention is usually preferred when appropriate. If we identify patients with pre-hypertension, lifestyle modification can go a long way to preventing or delaying the need for medication. Excellent studies have shown that salt reduction, especially in combination with the DASH diet, can significantly lower blood pressure (N Engl J Med, Vol. 344, No. 1 Â· January 4, 2001). (The DASH diet is not specifically low-sodium, but emphasizes fresh fruits, low refined carbohydrates, etc.). Some people with hypertension are more sensitive to salt than others, and African Americans in general benefit more from salt reduction than other ethnic groups.
Weight loss also helps lower blood pressure significantly in people who are overweight. Eliminating certain medications, such as NSAIDS (motrin, naproxen, aleve, etc.) and decongestants can help lower blood pressure. Most of these preventative measures eventually fail, perhaps due to an aging cardiovascular system, an inability to lose weight and exercise, genetic predispositions, or other factors.
Unfortunately for the “holistic” folks out there, research has shown that most hypertensive patients will require at least two medications to sufficiently lower blood pressure. Thankfully, most of these medicines are relatively cheap and safe (for instance, hydrochlorothiazide and lisinopril, two very effective medications, are each available from Target and Wal-Mart for $4, or in a combined pill for $4.)
So, we know a lot about hypertension and its connection to salt consumption–it’s an important connection, more so for some patients than others.
So why would a doctor promote salt purchase and use?
This recommendation flies in the face of decades of data and the recommendations of most of their colleagues. Thankfully, I have the writings of the author to work with.
His article is rather long and poorly written, but I’ll try to follow it section by section (the section divisions are his):
Dietary Villain or Foundation of Health?
In his introduction, the author sets up a nice straw man, says that he will review research, and then inserts his own “experiences“:
Government agencies, the American Medical Association, and many dietary groups all recommend a low-salt diet.
A review of the research literature, as well as my own clinical experiences have convinced me that unrefined salt is vital to good health.
The straw man here is the assertion that certain organizations deny that salt is necessary to health. It also asserts that certain “government agencies” and the AMA recommend low-salt diets. I searched the AMA website, including patient education sections. There is no “AMA policy” on salt intake. They recommend speaking with your doctor, and mention the connection between blood pressure and salt intake. They make no generalized recommendation on salt intake. One reason may be because the AMA does not make position statements on treatment issues, as far as I’m aware (I’m not a member).
The CDC also has no specific recommendations on its website regarding a low-salt diet. The Department of Health and Human Services publishes dietary recommendations for Americans (although I’m not sure who reads them), and they recommend a low-salt diet for certain people, and a general limit on sodium consumption to about a teaspoon a day.
There is also a subtle appeal to conspiracy by mentioning “big gubmint” and the AMA. Then there is the nearly-hidden reference to something called “unrefined salt”.
Hypertension and Salt
Let’s see what Dr. B. has to say.
First, most of the section is based on his “personal experience”, not actual data. But let’s let him tell the story:
[M]y experience with promoting a low-salt diet to treat hypertension was not successful. Not only did I find a low-salt diet relatively ineffective at lowering blood pressure, but I also found a low-salt diet made my patients miserable due to the poor taste of their low-salt food.
Many physicians have similar experiences. Low salt diets can be difficult to follow, but actual studies have found them to be effective in many patients, so his “experience” really doesn’t count for all that much when put next to large randomized controlled trials. His experience could reflect his patient population, his own abilities, or other random factors. Also, if he hasn’t kept data on how many patients have tried various interventions, their BP readings, etc, then his opinion means nothing.
It wasn’t until I began to look at my patients in a more holistic manner that I began to research the medical literature about salt. What I found was astounding; there is little data to support low-salt diets being effective at treating hypertension for the vast majority of people. Also, none of the studies looked at the use of unrefined sea salt, which contains many valuable vitamins and minerals such as magnesium and potassium, which are vital to maintaining normal blood pressure.
Wow, he’s right! Well not about the salt-hypertension link—the data for hypertensive patients is quite solid, as discussed above. But “unrefined sea salt” has not been subjected to much study. In fact, there are lots of substances that haven’t been studied—top soil, corn starch, saw dust—because, well, why would you? A study would be simple enough to conduct though, which would be better than “guessing” that it is good for you. Oh, and by the way, I’m not sure why unrefined salt would contain any vitamins at all—minerals, sure, vitamins, probably not.
He goes on to re-assert that ” [s]tudy after study has failed to establish a significant causal relationship between salt intake and hypertension.” He then makes an irrelevant statement that, according to a large government survey (hey, wait, I thought the government was the enemy in this argument—two demerits for inconsistency), “inadequate mineral intake (calcium, potassium and magnesium) is the dietary pattern that is the best predictor of elevated blood pressure in persons at increased risk of cardiovascular disease.” Well, that specifically says nothing about sodium. Two more demerits for non sequitur (Dear Reader, you simply must help me keep track of the demerits).
Salt and Heart Disease
This is where he begins to mix in some truth. The real outcome we care about is death from cardiovascular disease. There are very few studies looking at the effect of low-salt diets on this outcome. Most of the studies looked at blood pressure, and since lowered blood pressure is associated with lower rates of cardiac mortality, an extrapolation was made. It may be a logical extrapolation, but that doesn’t make it true prima facie.
However, since we know that lowering blood pressure is good, most studies focus on how to effectively lower blood pressure. It’s much easier to conduct studies on blood pressure then to do longer studies that wait for people to have heart attacks and die.
He also quotes on study in which the researchers said that, “It is also very hard to keep on a low salt diet.” That is a useful bit of information—if a treatment is too hard to adhere to, it will be less effective in real life. Of course, taking insulin is hard, losing weight is hard, quitting smoking is hard; that does not make them useless.
Next he mentions a study in which patients on low salt diets had an massive increase in rates of heart attack. He doesn’t cite it, I’ve never heard of it, I can’t evaluate the claim. I can say, however, that such a dramatic study would be a frequent topic of discussion among internists and cardiologists–it’s not.
Unrefined Salt and Health?
“We have established that a low-salt diet is not very effective at significantly lowering blood pressure in most people.”
“We” have established no such thing…in fact we have established the opposite in study after study. This probably means that the rest of the paragraph will be built on this false premise (an example of “begging the question”).
He then goes on to assert that low mineral levels are responsible for high blood pressure, and that “unrefined salt” is a good source of these minerals.
Call me crazy, but he made his first good point in the previous section, arguing against making extrapolations—then, he goes on to make a doozy–“if this, then maybe that and the other.” Two more demerits for inconsistency.
I don’t think I can handle more point-by-point refutation. Let’s just finish with some more of his unfounded assertions:
Since refined salt is a toxic substance, there should not be any refined salt in anyone’s diet.
Excuse me? It is? When did that happen?
However, there is a great difference between refined and unrefined salt. I recommend only the use of unrefined salt in one’s diet. This will supply the body with over 80 minerals that are useful for maintaining the normal functioning of the body. My experience has shown that the use of unrefined sea salt has not resulted in elevated blood pressure in my patients. The addition of small amounts of unrefined salt to food or cooking will not adversely affect blood pressure or other health parameters in someone with normal kidney function.
Enough with the “in my experience”! Prove, don’t assert!
there is considerable research indicating that unrefined salt can be an important part of a healthy diet
There is? I don’t know. He doesn’t cite any.
Now he makes the second good point of the article: there are many types of patients who do need to avoid salt. This is true, but if all the rest that he has written is true, including a connection between low-salt diet and heart attacks, how can this be true? One demerit for internal contradiction.
His summary section is just that–a summary of the above. I suggest reading it yourself if you so choose.
Take home points—follow the money
This article is not science. It makes unfounded assertions, reads the literature poorly, and contradicts itself in many places. It does, however, give links to purchase “unrefined sea salt”. You can get five pounds for $99.00 ($44.00 if you join now!). The same amount of table salt is about $5.00 at your local market. They also link to the woo-meister’s website, which also sells lots of stuff.
This is my first encounter with salt-woo, and hopefully my last. However, this guy’s office is down the street from me, and some of his patients have begun showing up at my door. I guess we’ll just have to stay tuned.